Crank-shaft-milling machine.



C. OVERGAARD.

CRANK SHAFT MILLING MACHINE.

APPLICATION FILED DEG.16, 1911.

4 SHEETS-SHEET 1.

Jim 610507" CHR/STE/V OVfRQ/MRD Patented Dec. 9, 1913.

Fittorr gy G. OVERGAARD.

CRANK SHAFT MILLING MACHINE.

APPLIOATIONEILED DEO.16, 1911.

1,080,576 Patented De0.9,1913.

4 SHEETS-$31231 2.

Wz'Znesses WNW Patented Dec. 9, 1913.

4 SHEETS-SHEET 8.

/ lmm IIIIIIHZ U. OVERGAARD.

CRANK SHAFT MILLING MACHINE.

APPLIOATION FILED DEG.16,1911.

0. OVERGAARD.

CRANK SHAFT MILLING MACHINE.

APPLICATION FILED DEG.1G, 1911.

Patented Dec. 9, 1913.

4 SHEETS-SHEET 4.,

p UNITE l CHRISTEIFOVERGAARID, OF COPENHAGEN, DENMARK.

CRANK-SHAFT-MILLING MACHINE.

To all whom it may concern:

Be it known that I, OHRISTEN Ovnnoaann, engineer, a subject of the Kingdom of Denmark, residing at No. 4 Amager Boulevard, Copenhagen, Denmark, have invented certain new and useful Improvements in Crank-Shaft-Milling Machines; and I do hereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

In my co-pending application Serial No. 666,280, filed Dec. 16, 1911, I have described an improved method of milling crank shafts or the like, in which the rough crank shaft vertically supported at a single point in a horizontally rotatory clamping table is milled by means of end milling cutters, which can be displaced in relation to each other, and which from different sides independent of each other can be moved toward, transversely to and parallel to the shaft, and the speed of each of which can be regulated in such a manner that vibrations of the shaft during the milling are prevented, and that consequently every source of inaccuracy is eliminated.

The objectof my present invention is to construct a machine for milling crank shafts in accordance with said method. This object I attain in the manner hereinafter set forth, reference being had to the accompanying drawings, in which- Figure 1 shows a front view of the ma chine partially in vertical section, Fig. 2 is a plan of the machine, Fig. 3 shows one of the cutter housings viewed from the center of the table, and Fig. 4 is a partially sectional view of the motor and the gearings between it and the shafts for different feeds, Fig. 5 is a vertical section through one of the slides which shows the motorand the gearings between it and the cutter spindle, Fig. 6 is a view of the lubricating ump and its connections, and Figs. 7 to 10 s ow various operation stages.

On the bedplate d is placed a revoluble table 6 provided with a rack f meshing with a pinion driven by the shaft G. So id table may be driven at variable speed from a motor I (Figs. 2 and 4), the shaft of which is connected to a shaft 11 mounted in a housing H and provided with a frictiondisk 19. which can be adjusted. lengthwise on the shaft by means of a handle 1.3. The disk 12 Specification of Letters Patent.

Application filed December 16, 1911.

the main shaft 11 in the housing Patented Dec. 9, 1913. Serial No. 666,279.

cooperates with a friction disk 14 fixed to the end of the shaft G, so that said shaft is rotated with different speeds according to the position of the friction disk 12. Upon the table e is placed a pair of clamp elements la, la, which hold the crank shaft, and are tightened b bolts or the like. The clamps can move iametrically over the whole of the table in such a way that the crank shaft can be rotated bodily about a center which is the center of the table, and at any radial distance therefrom desired. It is of course also powible to rotate the crank shaft, while the same is concentric with the center of the revoluble table.

The bedplate is, on both sides of the table provided with guides, and upon each of these are placed housings Z, l, which by the aid of screws m, m can be moved backward and forward upon the guides at different speeds dependent upon the adjustment of the gear box H. In the housings Z, l are placed slides a, n, which move vertically between four guides, whereby accurate and rigid guidance is insured. The vertical motion can 6. g. be produced by two screws 0, 0, which co-act with nuts upon the slides. The screws are driven by the shafts p, p. The shafts m, m, and 7), p are driven from H, (Fig. 4). Each of said shafts is provided with a conical pinion 15 engaging two conical pinions 16, 16 loosely mounted upon the shaft 11. Between each of said pairs of pinions 16 is arranged a couplingmember 17 by which said pinions can be connected to the shaft, and by means of a handle 18 can be brought in engagement with one or the other of said two pinions 16, thereby causing the corresponding pinion 15 and its shaft to rotate in one direction or in the other.

In order that the housings Z, Z can form a solid and reliable guide for the slides a, it, they are connected at the top by means of cross pieces (1, q. Motors 9-. r" are mounted in the slides n, a. Each of said motors drives through pinions 19, 1510 (Fig. 5) a shaft 21 mounted in the slide. Upon said shaft are loosely mounted two pinions 22, 23 of different size, engaging pinions 24-, 25 also of different size fixed to a second shaft 26 mounted in the slide a or a. By means of a coupling member 27 provided u oh a handle 28 one or the other of the pinions 22, 23 can be connected to the shaft 31 hereby causing the shaft 26 to be otated at a lesser or greater speed. Upon the shaft 26 are loosely mounted two pinions 29., 30 of diderent size, which engage pinions 31, 32, also of difierent size fixed to a hollow shaft 33 mounted in said slide 02 or so. By means of a coupling member 34 provided with a handle 35 one or the other of the pinions 29, 80 can be connected to the shaft 26, thereby causing the hollow shaft 33 to be rotated at a lesser or greater speed. The spindles s, s carrying the end milling cutters t, 25' aremounted in the hollow shafts 32 in such a manner that they revolve with said shafts, but are lengthwise movable in said shafts. 'llhe speed of the motors 134" can be varied by a controlling device 36 by means of which the current supply to the motor can be regulated. By means of the described arrangement the speed of the cutters i, t can be regulated independent of each other and to any desired extent. 0n the other end ot the cutter spindles s, s are crossheads u, u, which at the same time form thrust bearings for the spindles; the crossheads slide on the guides 'v, '2), and the spindles can travel out and in by aid of the guide screws to, w.

'lo ena is the crank shalt to be milled as near to the clamp as possible, there is provided beneath the revoluble table, and about the same center, a pit a, which also serves as a reservoir for the soap water or other lubricant, used during the milling. From the pit the soap water or other lubricant is pumped rip through the pipe y (Fig. 6) by a pump 3? driven by a motor 37 which delivers the soap water to pipes 38, 39 con nected to flexible tubes .2, a through which the soapy water is led to hollow spindles s, s and thence to the cutters t, 25 which it leaves just in front of each cutting edge.

When a crankshaft is to be milled the rough forging is placed in the machine in such. a manner that the first crank is fixed between the clamps 7c, is, which latter are then so adjusted that the axis of the shaft coincides with the center of the table. Then the upper end, that is, the first bearing part of the shaft can be milled. When this first bearing part is finished, the shaft is vertically displaced in the clamps k, is and again fixed in such a position that the first crank lies immediately over said clamps and that the front and back surfaces of said crank are placed arallel with the clamp slides. Then the camps are brought so tar out to the side, that the axis of the crank pin coincides with the axis of rotation of the table. llhe crank pin cannow for instance be made as shown in Fig. 7 by placing the cutters in position about halt way between those indicated by Figs 8 and 9, and the milling takes place by turning the table at the same time bringing the cutters nearer the center for every revolution of the table by turning the guiding screws w, w. "lt is to be remarked that when one cut is milled by one cl the cutters the table can continue quickly in the same direction until the metal is nearing the cutter on the opposite side, which meantime is adjusted to mill a new cut. These operations are discontinued of course when the pin has become round and of required diameter. As the work proceeds the milling is performed on a smaller and smaller radius, and it is therefore preferred by any known means to correspondingly increase the rotatory speed of the table, in such a manner that the work produced by the cutters per unit of time always is the same.

lit the crank pin is to he milled cylindrically, one can, when the right diameter is reached, place the cutters as shown in Fig.

5, then turn the table and simultaneously for every revolution of the table bring the cut ters sideward nearer the center of the pin until they are standing as shown in Fig. 6 just over thecenter; then a circular cylindrical surface, the height of which is equal to j the diameter of the cutters, is milled.

The milling of the trout and back surfaces a, c" takes place by setting the table in such way that these surfaces lie parallel with the direction of motion of the housings and by moving these forward and backward over the whole length of the surfaces, these surfaces can be finished completely on the machine. The end surfaces of the crank webs 10, 10" can be milled as shown in Fig. 8. The shaft is adjusted on the table in such a manner, that the axis of the table lies between the axisot the shaft and the axis of the pin. By milling the end surfaces of the webs with a joint center, the cranks are made lighter, and the corners are not so sharp. It is to be noticed, that with large cranks this operation'wonld practically be impossible on a crank shaft lathe, as this would demand a machine of exceptional, dimensions. Afterhaving completed the first crank in the way described, the shaft is again vertically displaced in the clamps k, k. and fixed in such a position that its second bearing part can bemilled. Thereafter-the shaft is again vertically displaced and the second crank is milled and so on. When the upper half of the shaft is milled, the shaft is turned about and the milling is started from the opposite end. i

Having now particularly described and ascertained the nature oi" my said invention, and In what manner the same is to be pertermed, I declare that whatl claim is:

1. In a crank milling machine, the combination with horizontally revoluble clamping table and beneath said table adapted to take the major portion of the length of the shaft vertically fixed at one point in, said clamping table, of end milling cutters disposed in the immediate vicinity of the point of support of said shaft, means for displacing said cutters in relation to each other, means for moving said cutters from different sides independent of each other toward, transverse/1 to and arallel to the shaft, and means y which t e rotary speed of said cutters can be varied independent of one another.

2. In a crank shaft milling machine, the combination of a horizontal table revoluble about a vertical axis, clamp elements for supporting at one point the shaft held vertically, which clamp elements can slide diametrically upon said table, and a pit beneath said table adapted to take the major portion of the length of the shaft, with end milling cutters, means for displacing said cutters in relation to each other, means for moving said cutters from different sides independent of each other toward, transversely to and parallel to the shaft, and means by which t e rotary speed of said cutters can be varied independent of one another.

3. In a crank shaft milling machine, the combination of a clamp revoluble about a vertical axis, in which the shaft is adapted to be vertically held, with end milling cutters, spindles carryin said cutters, means for moving said spindles in three different directions perpendicularly to each other, means for rotatin said spindles, frames for carrying said spindles and their rotating motive elements, and vertical guides for said frames, which guides are rigidly interconnected at the top and bottom.

In testimony whereof, I afiix my signature, in presence of two witnesses.

CHRISTEN OVERGAARD.

Witnesses:

MARCUS W. Lonnnn, Cam HOBTENER. 

